JPS61219841A - Apparatus for mounting contact type temperature sensor - Google Patents

Abstract

PURPOSE:To always stably and accurately detect temp. without being under the effect of a mounting state, by providing a support stand for supporting a heat sensitive element and interposing a coil spring between the support stand and the heat sensitive element or a contact plate. CONSTITUTION:A contact plate 2 having a heat sensitive element 1 adhered thereto is mounted to a support stand 6 through a coil spring 5 so as to be freely move by the action of the coil spring 5. Thus constituted contact type temp. sensor is contacted with a fixing roller 3 under pressure. When the contact plate 2 was mounted to the fixing roller 3 in parallel thereto, said contact plate 2 is uniformly and closedly contacted with the fixing roller 3 to perform the accurate detection of temp. When the contact plate 2 was obliquely mounted to the fixing roller 3, only one end of the contact plate 2 at the corner thereof is contacted with the fixing roller 3 at first and the part of the coil spring 5 in the side nearest to said contact part is brought to a compressed state while the coil spring in the opposite side comes to an extended state and the contact plate 2 is uniformly and closely contacted with the surface of the fixing roller 3.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a contact temperature sensor used for detecting the temperature of the surface of a stationary body or a rotating body, such as the surface of a fixing roller of a copying machine.

(Prior art) Conventional contact type temperature sensor/for example, JP-A-55-782
The device described in Publication No. 24 has a structure as shown in FIG.

That is, a contact plate 2 made of a spring material with the heat-sensitive element 1 attached to one end is pressed against the fixing roller 3 of the copying machine, the surface temperature of the fixing roller 3 is detected, and the lead of the heat-sensitive element 1 is pressed against the fixing roller 3 of the copying machine. Output is taken out to the outside via lines 4a and 4b.

(Problem to be Solved by the Invention) However, in such a structure, the contact plate 2 is connected to the fixing roller 3.
If the heat-sensitive element 1 and the fixing roller 3 are not attached parallel to the surface thereof, the contact between the heat-sensitive element 1 and the fixing roller 3 will be uneven, resulting in a problem that accurate temperature detection cannot be performed.

(Means for Solving the Problem) In order to solve the above problem, in the present invention, a support stand for supporting the heat-sensitive element is provided, and a gap between the support stand and the support body (contact plate) for the heat-sensitive element is provided. A coil spring is interposed between the two.

(Function) The inclination between the support base and the fixing roller is absorbed by the expansion and contraction of the coil spring, and the heat-sensitive element or its holder (contact plate) always contacts the surface of the fixing roller in a normal state.

(Example) As shown in FIG. 1, a contact plate 2 to which a heat-sensitive element 1 is adhered is attached to a support base 6 via a coil spring 5, and the contact plate 2 is made to move freely under the action of the coil spring 5. put. The contact type temperature sensor configured as described above is brought into pressure contact with the fixing roller 3.

When the contact plate 2 is installed parallel to the fixing roller 3, the contact plate 2 is evenly and closely contacted with the fixing roller 23, and accurate temperature detection is performed without any problems.

Next, if the contact plate 2 is installed at an angle with respect to the fixing roller 3 as shown in FIG. The coil spring 5 on one side is in a compressed state, and the coil spring on the opposite side is in an expanded state, so that the contact plate 2 is brought into even and close contact with the surface of the fixing row 23.

Note that the diameter of the coil spring 5 is the maximum dimension of the contact surface between the contact plate 2 and the fixing roller 23 (in this case, since the fixing roller 23 is cylindrical, the axial contact length of the fixing roller 3 is the maximum dimension) For mechanical reasons, the smaller the diameter, the better the adhesion can be obtained.

Moreover, the positional relationship of the structure of the contact type temperature sensor of the present invention is as follows:
The structure is not limited to the structure shown in FIG. 1, and for example, as shown in FIG. The contact plate 2 is slidably attached to the support column 7 as shown in part 0 in FIG.
Good effects can also be obtained by attaching the coil spring 5 to the support base 60 through the hole 8 of the support base 60, and interposing the coil spring 5 between the support base 60 and an arbitrary position between the two ends.

The contact type temperature sensor configured as described above is brought into pressure contact with the fixing roller 3 to detect the surface temperature of the fixing roller 23, and the output is taken out to the outside via the lead wires 4a and 4b of the heat sensitive element 1.

In the case of the structure shown in FIG. 1, which is the first embodiment, the heat-sensitive element 1 is a plate-shaped thermistor with a thickness of 3.2 + m, and the contact surface in the axial direction of the fixing roller is made of epoxy resin with a thickness of Q, 1 + m +). It was adhered to a stainless steel contact plate 2 with a length of 5 m, and the coil spring was a piano wire with a wire diameter of 0.7 gourd wound to a low diameter. Contact plate 2 to which the heat-sensitive element 1 is adhered
and a coil spring q are attached to a support base 6 made of heat-resistant resin and brought into pressure contact with the fusing roller 3 of the copying machine, and the output of the contact type temperature sensor is fed back to the heating rung control circuit of the fusing roller 3, and the surface of the fusing roller is As a result of controlling the temperature, the detected temperature on the surface of the fixing roller 23 when the contact type temperature sensor is installed parallel to the fixing roller 3, and the detected temperature on the surface of the fixing roller 23 when the contact type temperature sensor is installed at an angle with respect to the fixing roller 3. 23 The temperature difference (ΔT) from the detected temperature on the surface can change as shown in FIG. 4 as the angle (θ shown in FIG. 2) changes when the contact type temperature sensor is attached to the fixing roller 3. I understand.

In other words, if the mounting angle θ is within ±10 degrees, the contact plate 2 will maintain close contact due to the action of the coil spring 5, and the angular tolerance of this mounting is limited by the contact type temperature sensor or copying machine during mass production. The dimensional tolerances of the main body for installation are sufficiently satisfactory even when angle variations are taken into consideration, and extremely excellent installation stability can be obtained.

In the case of the first embodiment, the contact plate 2 and the fixing roller 3
As a result of carrying out an experiment similar to that of the first embodiment, the maximum dimension of the contact surface was set to 10, the diameter of the coil spring 5 was set to 7, and the diameter of the coil spring 5 was made smaller than the maximum dimension of the contact surface. Good adhesion was maintained up to an angle of 15 degrees.

In the case of the second embodiment, a contact type temperature sensor having the structure shown in FIG.
As a result of an experiment using a coil spring with a diameter of 10 degrees, good adhesion was maintained up to an angle of ±10 degrees.

In the case of the second embodiment, the contact plate 2 and the fixing row 23
The maximum dimension of the contact surface of 10 II l 1111 The diameter of the coil spring 5 was 711 I1 m, and as a result of experiments with the diameter of the coil spring 5 smaller than the maximum dimension of the contact surface, good adhesion was maintained up to an angle of ±15 degrees when mounting p. Ta.

(Effects of the Invention) As described above, according to the present invention, the structure is extremely simple, the installation is not affected by the condition, and stable and accurate temperature detection can be performed at all times, so it is extremely practical. Useful.

[Brief explanation of the drawing]

Fig. 1 is an embodiment of the contact type temperature sensor mounting device of the present invention, Fig. 2 is an explanatory diagram of the operation of the embodiment of Fig. 1, Fig. 3 is another embodiment, and Fig. 4 is the device of the present invention. FIG. 5 is a diagram showing the basic structure of a conventional contact type temperature sensor mounting device. DESCRIPTION OF SYMBOLS 1...Thermal element, 2...Contact plate, 3...Fixing roller, 4a+4b...Output take-out lead wire,
5... Coil spring, 6... Support stand. Figure 1 a4b Figure 3

Claims (3)

[Claims] (1) The feature includes a contact plate to which a heat-sensitive element is adhered, a support for the contact plate, and a coil spring provided between the contact plate and the support to support the contact plate so as to be able to slide up and down. Mounting device for contact type temperature sensor. (2) Claim (1) characterized in that the diameter of the coil spring is smaller than the maximum dimension of the contact surface of the contact plate.
Mounting device for the contact-type temperature sensor described in . (3) A heat-sensitive element is provided at one end of the contact plate, the other end is slidably supported on a support base, and a coil spring is provided at an arbitrary position between the two ends. A mounting device for a contact type temperature sensor according to item (1).